How do you reduce the number of unrealistic facility locations when using loc/alloc?

583
3
Jump to solution
09-06-2012 07:56 AM
Highlighted
New Contributor II
I am attempting to determine an optimal station location for a fire station using the maximize coverage setting.  I typically set a point grid every with 1000 foot spacing to load into the facilities points for my potential station locations.  On this last model I ran, it placed a station in the "clover leaf" of a 2-highway intersection.  While this makes perfect sense from a pure street network standpoint, its not feasible.  How do you guys manage this kind of issue, apart from going through each facility loaded and removing those that don't make sense.  In my case, this wouldn't really be feasible.  thx for any thoughts!
Tags (2)
Reply
0 Kudos
1 Solution

Accepted Solutions
Highlighted
Esri Regular Contributor
First I would like to say that you can control where the points load by using a query. That is, at load locations time you can specify that the point should not locate on highways or ramps. To do this you use the Build Query option where the query could exclude roads with say CFCC code A63 etc (based on your data). You can read more about it in the section titled "Snapping environment with Build Query" here:
http://resources.arcgis.com/en/help/main/10.1/index.html#//00470000003n000000

Another way to generate candidate facility locations (that I like to use) is a combination of two GP tools. These are the Feature To Point and Create Random Points. So you can start by selecting a set of roads that meet your criteria for locating a facility and then use the Feature To Point on this selection. It will create one point per street. If this is enough you can load them as candidate facilities. If they are too many or too dense, use the Creaet Random Points to further subset or randomly select from these points a set of points that are say every 1000 foot apart (and you can specify how many you want).

Just remember, it is better to logically narrow down the candidate set of facilities so that you can get a good feasible location. So if many of the roads/locations are not available for building a fire station then exclude them before you run the Feature to Point tool

Regards,
Jay Sandhu

View solution in original post

Reply
0 Kudos
3 Replies
Highlighted
Esri Regular Contributor
First I would like to say that you can control where the points load by using a query. That is, at load locations time you can specify that the point should not locate on highways or ramps. To do this you use the Build Query option where the query could exclude roads with say CFCC code A63 etc (based on your data). You can read more about it in the section titled "Snapping environment with Build Query" here:
http://resources.arcgis.com/en/help/main/10.1/index.html#//00470000003n000000

Another way to generate candidate facility locations (that I like to use) is a combination of two GP tools. These are the Feature To Point and Create Random Points. So you can start by selecting a set of roads that meet your criteria for locating a facility and then use the Feature To Point on this selection. It will create one point per street. If this is enough you can load them as candidate facilities. If they are too many or too dense, use the Creaet Random Points to further subset or randomly select from these points a set of points that are say every 1000 foot apart (and you can specify how many you want).

Just remember, it is better to logically narrow down the candidate set of facilities so that you can get a good feasible location. So if many of the roads/locations are not available for building a fire station then exclude them before you run the Feature to Point tool

Regards,
Jay Sandhu

View solution in original post

Reply
0 Kudos
Highlighted
MVP Esteemed Contributor
That's a really cool procedure Jay.  Thanks for sharing!
Reply
0 Kudos
Highlighted
New Contributor II
Thanks for this advice Jay.  I use a similar approach, using Hawth's tools to create a 1000' grid equal to my city boundaries shapefile to develop candidate locations.  It sounds like your suggestion is to continue with that approach, but then snap to roads, excluding those roads that are not feasible for the location - like a highway, or onramp.  That's a great idea.  Thank you.
Reply
0 Kudos